<!DOCTYPE html>
<html>
<head lang="en">
    <meta charset="UTF-8">
    <title></title>
</head>
<body>
<div></div>
<script src="js.js"></script>
<script>
//    var a=I("div")
//    console.log(a.constructor());
    var arr=[1,2,3];
    var arr1=I.map(arr,function(v){
        return v*2
    })
    console.log(arr1);
</script>
</body>
</html>